Water‐Splitting “Without Water”: Splitting of the Crystallised Water of Hydrated Salts

K Klara Rüwe (Department of Biology and Chemistry The Electrochemical Energy and Catalysis Group University of Osnabrück Barbarastrasse 7 49076 Osnabrück Germany) S Shirui Wang (Department of Chemistry, School of Sciences, Great Bay University) T Tom Bookholt (Department of Biology and Chemistry The Electrochemical Energy and Catalysis Group University of Osnabrück Barbarastrasse 7 49076 Osnabrück Germany) J Julia Brune (Department of Biology and Chemistry The Electrochemical Energy and Catalysis Group University of Osnabrück Barbarastrasse 7 49076 Osnabrück Germany) H Hannelore Schmidt (Faculty of Engineering and Computer Science Laboratory for Organic Chemistry and Polymer Chemistry University of Applied Sciences Osnabrück P.O. Box 1940 49009 Osnabrück Germany) M Marius Behnecke (Faculty of Engineering and Computer Science Laboratory for Organic Chemistry and Polymer Chemistry University of Applied Sciences Osnabrück P.O. Box 1940 49009 Osnabrück Germany) S Svea Petersen (Faculty of Engineering and Computer Science Laboratory for Organic Chemistry and Polymer Chemistry University of Applied Sciences Osnabrück P.O. Box 1940 49009 Osnabrück Germany) C Claudia Hess A Alex M. Ganose (Department of Chemistry Molecular Sciences Research Hub White City Campus Imperial College London Wood Lane London W12 0BZ UK) H Helmut Schäfer (Department of Biology and Chemistry The Electrochemical Energy and Catalysis Group University of Osnabrück Barbarastrasse 7 49076 Osnabrück Germany)

Abstract

Abstract In contrast to the liquid phase of water, the structural molecular realities of H 2 O molecules embedded in crystallised salts vary little and can be precisely determined. However, this water, which is neither in the liquid nor in the gas phase, has not yet been used in water electrolysis. Here, we demonstrate that water electrolysis can be achieved without the addition of (liquid) water through experiments with a wide range of hydrated salts and organic solvent suspensions. We obtain an excellent correlation between the position of the FTIR O─H stretch vibration of the hydrated salts and the onset of the OER potential from CV measurements. Together with first‐principles density functional theory calculations, we demonstrate that intramolecular bonds in crystallised water can be effectively controlled through choice of the inorganic salt. Targeted manipulation of the bonds in the H 2 O molecule is a promising new approach to more efficient hydrogen production.

Article Details

Volume / Issue Vol. 65, Issue 4
Published January 22, 2026
ISSN 1433-7851
Publisher Wiley

Journal Info

Angewandte Chemie International Edition

Wiley

ISSN: 1433-7851 Physical Sciences

Authors (10)

K

Klara Rüwe

Department of Biology and Chemistry The Electrochemical Energy and Catalysis Group University of Osnabrück Barbarastrasse 7 49076 Osnabrück Germany

S

Shirui Wang

Department of Chemistry, School of Sciences, Great Bay University

T

Tom Bookholt

Department of Biology and Chemistry The Electrochemical Energy and Catalysis Group University of Osnabrück Barbarastrasse 7 49076 Osnabrück Germany

J

Julia Brune

Department of Biology and Chemistry The Electrochemical Energy and Catalysis Group University of Osnabrück Barbarastrasse 7 49076 Osnabrück Germany

H

Hannelore Schmidt

Faculty of Engineering and Computer Science Laboratory for Organic Chemistry and Polymer Chemistry University of Applied Sciences Osnabrück P.O. Box 1940 49009 Osnabrück Germany

M

Marius Behnecke

Faculty of Engineering and Computer Science Laboratory for Organic Chemistry and Polymer Chemistry University of Applied Sciences Osnabrück P.O. Box 1940 49009 Osnabrück Germany

S

Svea Petersen

Faculty of Engineering and Computer Science Laboratory for Organic Chemistry and Polymer Chemistry University of Applied Sciences Osnabrück P.O. Box 1940 49009 Osnabrück Germany

C

Claudia Hess

A

Alex M. Ganose

Department of Chemistry Molecular Sciences Research Hub White City Campus Imperial College London Wood Lane London W12 0BZ UK

H

Helmut Schäfer

Department of Biology and Chemistry The Electrochemical Energy and Catalysis Group University of Osnabrück Barbarastrasse 7 49076 Osnabrück Germany